Popular Science Monthly/Volume 73/July 1908/Needed: A System of Aquatic Farming
|NEEDED: A SYSTEM OF AQUATIC FARMING|
By Professor HERBERT OSBORN
OHIO STATE UNIVERSITY
THERE is a natural resource available in many parts of the country, indeed, on a large number of farms or in larger unused tracts of the entire Atlantic and Mississippi Valley region, that is not only almost wholly neglected, but the neglect of which involves a number of phases of economic loss. This loss becomes more serious and the reparation the more difficult as time passes, and hence a note of warning and appeal seems justified.
The present tendency is to reduce not only all accessible forest areas to ordinary farm cultivation, but by drainage of all possible swamp areas to still further increase the area for ordinary tillage and to decrease those tracts which have in some degree the function of holding and regulating the outflow of our rainfall.
Without attempting to discuss all the economic problems connected with this phase of the subject, we may note that it affects the constancy of water level over considerable areas, the flow of streams with its bearings on flood disasters and navigation, but perhaps more vitally the carriage of fertility from the farming regions to the sea, where, if it ever becomes available as a human resource, it is so remotely advantageous to the farm or to the nation that it must be counted an economic loss.
The assumption seems to have been, based, doubtless, on our knowledge of but one kind of farming, that every bit of land not under ordinary farm culture was a loss, and therefore to be transformed as rapidly as possible to cultivated fields. To this end, forests have been felled, and lowland swamps and marshes, even including many extensive and valuable bodies of shallow water, have been drained. This means that instead of acting as natural reservoirs and conservators of moisture and fertility, their surplus moisture content has been discharged as rapidly as possible into the rivers and so on to the seas.
Before making some suggestions as to systems of farming by which it seems possible to avoid this waste, and, on the other hand, to develop some most productive sources of wealth, it will be in place to call attention to the capacity for production resident in every permanent body of water.
Every one is familiar with the rank growth of swamps and lowlands and the most superficial observation will reveal the enormous masses of plant life growing in bodies of still water, or even in running water where the bottom will permit the rooting of the plant. But in addition to this evident growth there is an enormous development of life, microscopic or transparent and invisible except when collected and studied by proper methods, which, in rapidity of growth and amount of mass may far outclass the visible portion. Some of this becomes apparent as green scum or as floating masses when its growth exceeds the capacity of the aquatic animals to consume it. Sometimes these minute algae become a great source of annoyance in water supplies if for any reason their multiplication is unchecked, since they give offensive odors and taste to the water.
It has been estimated that the rate of development in some of these organisms is such that the possible progeny of one individual would suffice to fill all the waters of the globe in less than a week.
This is significant to us here simply as showing the enormous possibility of these organisms in utilizing water and air in the formation of vegetable substance, which substance may, with proper utilization, be transformed into fertilizing agents for the production of valuable plant crops or into animals having direct commercial value. To understand this process, let us consider for a moment the relations existing among aquatic organisms. The algæ may be considered among the more simple and these develop with only water and air or the other inorganic contents of water, but they furnish food for an innumerable host of microscopic animals such as amœbæ, rotifers, etc., and these in turn are fed upon by others, such as microscopic Crustacea, which again form an important part in the diet of young fishes. These, when grown, or after furnishing the basis of food for other larger species, may reach our tables as human food. This, however, is but one line of transformation, as we have fishes of very different habits utilizing different kinds of aquatic life as food.
Where the life taken from the water does not balance the production, or where this product is not drained off into the sea, the accumulation of organic debris forms at the bottom a mass of richest organic matter, which by its decomposition may in a large part result in marsh gas, and in this form escape into the air.
Having indicated the possibility of an unworked phase of agriculture, or aquaculture, let us now turn to some of the possible lines of development in this field.
We have in America practically no established system of cropping our water areas. It is true that some progress has been made in the sponge farming of Florida, and oyster farming in Rhode Island, Connecticut, Virginia, North Carolina and Louisiana, but even these need further development to utilize the natural possibilities.
But so far as fresh-water culture goes, there is scarcely a beginning. Something has been accomplished in fish culture in some sections, but even here the full utilization of the resources of a body of water are but poorly accomplished. A few sporadic efforts have been made here and there in the culture of frogs and turtles, but how many of them with such attention to the subject as to warrant the term culture? In fact, these efforts have often resulted in failure and their projectors looked upon as visionaries, worthy the contempt of the hero in the "Virginian."
The farmer who drains and cultivates an acre of swampy land on his farm gains that much additional space for his ordinary culture and for a time at least it may be unusually productive as it contains the accumulated organic debris of years, but would it not be far greater wisdom to dredge out occasionally a portion of this accumulation to spread upon the higher ground and keep the acre as a source of fertilizing material for the years to come. This seems all the more desirable when it is remembered that this basin must collect quantities of the finest and most fertile parts of the soil washed from the higher ground. Moreover, I hope to show that there is good reason to expect that the acre can be made so productive over and above this function of conserving fertility that it will be worth more in water than it could be as cultivated land.
What is needed in the matter of utilization of our great tracts of marshy or swampy land is some such systematic study and the development of some such adapted system as is in progress of development in the systems of "dry farming" in the arid or semi-arid regions of the west—a system which will intelligently conserve and utilize our heritage of water, not throw it ignorantly away and reduce our uplands to a condition of sterility.
Frog farms, turtle farms, fish farms by themselves might be put in the same category as skunk farms and fox farms; useful to utilize certain minor tracts of otherwise worthless land, but what is needed, if any general good is to follow, is a rational system applicable to the treatment of all tracts of level swampy land, especially those at the head waters of the great river systems and in the coastal swamps of the Great Lakes and river deltas—in fact, to all areas where a fairly constant water level is possible.
It is evident that in the nature of things wherever private ownership exists, or is possible, the effort inevitably will be toward gaining the largest immediate return from any such area, and the only hope of preserving these swampy tracts as reservoirs of water will be to hold them as public reservations or to devise some system of production which will make them more profitable with the water retained than they can be with the water removed. Hence an extended and careful study of the crops available for culture in such tracts becomes a pressing necessity. Such a study will of necessity involve years of investigation, both of the practises in countries where some such systems exist and of possibilities under our own conditions of available crops, markets, machinery, etc.
A short résumé, however, of some of the crops which already have some claim to notice and those which give promise of availability will help to show the possibility and practicability of such a system.
Among the plant crops which may be mentioned are water cress, which is already an article of considerable commercial value, but probably much less used in this country than elsewhere and doubtless much less than if the supply were increased. Methods of its culture are, of course, well known and would be simply a matter of adaptation to particular areas. The cranberry is also a well-known crop, adapted to bog or swamp conditions and for which there is unlimited demand.
Some of the marsh grasses, cat tails, rushes and other plants make a most abundant growth, and in association with other crops could no doubt be cultivated to good advantage. The basket willows are of great value and are used extensively in the manufacture of baskets, an industry which is capable of much expansion. The pond lily surely offers an opportunity for a most valuable aquatic crop, if systematically cultivated and harvested, especially in the vicinity of large cities and popular excursion resorts.
We may mention, also, the development of the industry, based on the slough-grasses of the northwest, including the manufacture of binding twine, mattings or carpetings and furniture. This utilizes an extensive area of wet land, not available for other crops, and which, if retained for this crop, doubtless could be utilized also in the culture of some other more distinctly aquatic crop. Other fiber plants are a possibility.
Of animal crops which are already known, fish culture is the most extended, but in general this is not reduced to a systematic farming basis. I can recall the furore created some twenty-five or thirty years ago, in connection with the introduction and proposed production of carp, but so far the carp industry in this country is mainly confined to that grown without attention, and gathered indiscriminately by fishermen without reference to any private rights. The market for this fish has, however, greatly increased and in centers where there is a large European population, as in New York City or Chicago, immense quantities are sold, and it is claimed that these people prefer carp to other fish which are greater favorites with American tastes. Under other names carp are sold to a considerable extent in our markets and, under such disguises as "smoked sturgeon," may pass as a distinct delicacy. This fish, on account of capacity for rapid multiplication and growth in restricted quarters and in ponds with abundant vegetation, is, perhaps, one of the most available for systematic cultivation. Other fishes, such as catfish and some of the species of bass, could be utilized in certain situations to good advantage.
While frogs have not been, as yet, a very common article on our markets, I do not know that the market has ever been over-stocked, and in the vicinity of large cities it would seem that a much larger quantity could be disposed of. As it is, immense numbers are utilized in the laboratories of schools and colleges, this demand being met for the most part by the capture of frogs in natural ponds. Crayfishes have not attained any special market value in the majority of markets, but I am told that they are sold to a great extent in New York City, and I see no reason why they should not be used as much as shrimp. Terrapin and no doubt other species of turtles could be marketed in much greater numbers than they are at present if their cultivation were systematized and markets properly handled. Both ducks and geese, while reared, so far as domestic species are concerned, very largely on land, would no doubt thrive better and get the best part of their growth on aquatic plants which form the greater part of their native food. They could be readily cultivated in connection with other crops.
The shells of fresh-water clams have been the basis for the establishment of some extensive button factories and the pearls that they produce have furnished a livelihood to a considerable number of individuals. But it is said that many of the factories have had to close on account of the exhaustion of the clams in adjacent streams. Doubtless, some reasonable system of gathering the shells or providing for the propagation and growth of successive generations would easily make this a permanent crop in suitable waters.
Alligator hides have a high commercial value and are all too scarce, with good prospect of disappearance from the extermination of the ungainly animal that produces them. I do not know that an alligator farm, fenced out in a suitable swamp or bayou, would be a commercial success, but it would seem well worth while to experiment in some of the swampy wastes in the domain of this prince of reptiles.
It may be somewhat remote, but it seems conceivable that it would be possible to utilize some fur-bearing animals in this direction, as, for instance: the beaver, muskrat, and possibly the otter, as these animals could certainly be colonized in suitable localities where an abundant water supply at a fairly constant level is available. As to possibilities of securing any regular crop from such animals, we have little data to guide us, but we know that under natural conditions they multiply at a fairly rapid rate. Muskrats in some localities are caught and marketed for food as well as for the skins.
With regard to salt or brackish water crops, we have already a good deal of knowledge, and with some animals and for certain localities quite thoroughly organized systems of cropping have been established; for instance, the sponge farms in Florida and oyster farming in some of the Atlantic states. The latter, however, are by no means so fully regulated as to secure the best results, as is shown by the exhaustive discussion of the subject by Professor Brooks. His estimate that the product from Chesapeake Bay of $2,000,000 annually, could and should be increased to $60,000,000, has, I believe, never been challenged, and indicates the possibilities. There are other marine forms like lobster, crab, shrimp and turtles which would lend themselves to similar definite systems of cultivation, and in fact a study of the basis for such systems has been in progress in the Bureau of Fisheries for many years past. It is necessary, however, that the results be carried into definite regulations or embodied in appropriate legislation in order to secure perpetuity in the crops and the most profitable returns.
In many instances, in both salt and fresh water areas, there will need to be entirely new legislative enactments providing for the regulations of water areas in which certain more or less sedentary animals may be cultivated. For such as migrate freely in the open waters there is perhaps no better policy than to permit capture by any individual under such restrictions as to season and quantity as may serve to protect the future supply. If animals have a fixed habitat and are capable of artificial propagation or culture, there is no logical reason why a person who plants and cares for such a crop should not be protected in the right to harvest it. Under existing laws, however, there is great difficulty in securing such rights, as all waters which have any connection with navigable streams or lakes are assumed to be public property. It would be entirely practicable, however, to guard the rights of property in the bottoms or shores without interfering in their public use for navigation, pleasure or even for fishing for such forms as are migratory. These are questions, however, which can be worked out when once the advantages of systematic cropping of water areas is fully recognized.
Aside from measures which utilize existing areas of swamp it appears to me that great advancement may be made in the combination of certain land and water crops, for instance, in a tract of marshy land having practically a constant level it would seem possible to alternate strips of land and water by the use of suitable dredging appliances, the land portion being utilized for the cultivation of such intensive crops as celery, asparagus, onions, strawberries, blackberries, etc., the fertility being maintained by adding dredged materials from the bottom of adjacent water strips. The water strips could then be utilized in the culture of such aquatic forms as fish, frogs, clams, turtles, ducks, etc., as may have the greatest value in the particular localities. By these methods we should avoid the loss incident upon constant drainage of water, secure an unfailing irrigation for crops cultivated in the land portion, secure a valuable source of fertility, and at the same time a valuable aquatic crop. Systems of this character, however, would be gradually developed and modified to suit conditions of particular localities.
A recent number of the National Geographic Magazine gives the areas of swamp lands in the United States (not including Alaska) at sixty millions of acres, almost entirely in the humid regions of the Atlantic slope and the Mississippi Valley.
A bulletin issued later by the U. S. Department of Agriculture gives an estimate of 77,000,000 of acres for swamp and overflowed lands and claims a possible reclamation of practically this entire area.
Both of these authors put great stress upon the wealth to be gained by the drainage of this area, and discuss some of the great national and state projects already in view, but no hint is given by either that any part of this vast area could be put to useful service except by disposing of the water.